We examine classroom video recordings as a means of supporting the learning of teacher communities. Drawing on a longitudinal professional development program for middle years mathematics teachers in the USA, we first outline two contrasting episodes in which the teachers analyzed same segments of classroom video in two different points in the program, 2 years apart. We document that the teachers considered dramatically different aspects of video-recorded instruction as relevant to their professional interests and learning in the two episodes. We then analyze the episodes, and the intervening developments, from point of view of the community documentational genesis. In doing so, we highlight the teacher community’s creation of shared repertoire of ways of reasoning.